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Evaluation of effective carrier system and function on hydrocarbon accumulation in Gaoyou Sag,Subei Basin,China
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作者 李浩 高先志 +2 位作者 孟晓燕 赵赟龙 张明 《Journal of Central South University》 SCIE EI CAS 2013年第6期1679-1692,共14页
Effective carrier system comprises carrier beds which transport hydrocarbons. The spatial and temporal effectiveness of carrier system is identified according to the relevance of hydrocarbon show, hydrocarbon inclusio... Effective carrier system comprises carrier beds which transport hydrocarbons. The spatial and temporal effectiveness of carrier system is identified according to the relevance of hydrocarbon show, hydrocarbon inclusion and sealing ability of fault to hydrocarbons distribution, together with matching relation of activity history of fault and hydrocarbon generation history of source rock. On the basis of the above considerations, transporting ability of effective carrier system can be evaluated using parameters such as fluid potential, porosity and permeability, spatial coefficient of effective pathway as well as activity rate of fault. Additionally, a new concept of"transporting threshold porosity" was proposed. Five styles of effective carrier systems were established in Gaoyou Sag, displaying either layered or zonal distribution characteristics, and transporting time ranges from the sedimentary time of Ezdz to early stage of sanduo uplift. Effective carrier systems can be described to be lowly-efficient and highly-efficient. Major faults (convex or steep fault plane) with activity rate greater than 20 m/Ma and structure ridges of sand layers with spatial coefficient of effective pathway greater than 25% are defined to be highly-efficient carrier beds. Hydrocarbons are concentrated around high-efficient carrier beds and E1 f traps of northern shanian area are predicted to have great potential. 展开更多
关键词 effective carrier system transporting threshold porosity of carrier beds fluid potential hydrocarbon migration GaoyouSag
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Iterative Block DFE for Underwater Acoustic Single Carrier System 被引量:4
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作者 Sun Haixin Guo Yuhui +1 位作者 Kuai Xiaoyan Cheng En 《China Communications》 SCIE CSCD 2012年第7期121-126,共6页
Abstract: In order to gain a better performance and reduce the computational complexity of the filter design in the underwater acoustic single car rier system, a new Iterative Block DFE (IBDFE) is proposed, which o... Abstract: In order to gain a better performance and reduce the computational complexity of the filter design in the underwater acoustic single car rier system, a new Iterative Block DFE (IBDFE) is proposed, which operates iteratively on blocks of the received signal, and fully implements its filtering operations by Discrete Fourier Trans forms (DFTs). Two design methods are consid ered for IBDFE: one is HDIBDFE, and the oth er is SDIBDFE. In this paper, the first one is a dopted. In this scheme, 展开更多
关键词 underwater acoustic system single carrier IBDFE
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Guaranteeing Wireless Communication Reliability via an Extended Hybrid Carrier System
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作者 Ge Song Xiaojie Fang Xuejun Sha 《China Communications》 SCIE CSCD 2023年第7期192-202,共11页
In this paper,we propose an extended hybrid carrier system based on the weighted fractional Fourier transform to ensure the reliability of wireless communication.The proposed scheme improves the dispersion and compens... In this paper,we propose an extended hybrid carrier system based on the weighted fractional Fourier transform to ensure the reliability of wireless communication.The proposed scheme improves the dispersion and compensation capabilities of the hybrid carrier system for channel fading through the design of the signal power distribution,which has greatly reduced the probability of high-power distortion of the signal and improved the bit error rate performance as a result.Theoretical analysis has shown the superiority of the extended hybrid carrier system.With a lower cost of computational complexity increment,the proposed scheme obtains a performance improvement without occupying additional time-frequency physical resources.Compared with the existing hybrid carrier scheme,numerical simulation results have shown that the proposed extended hybrid carrier scheme has better anti-fading performance under the doubly-selective channel and improves the reliability of the wireless communication system effectively. 展开更多
关键词 extended hybrid carrier weighted frac-tional Fourier transform bit error rate doubly-selective channel
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Mesh model building and migration and accumulation simulation of 3D hydrocarbon carrier system
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作者 GUO Qiulin LIU Jifeng +6 位作者 CHEN Ningsheng WU Xiaozhi REN Hongjia WEI Yanzhao CHEN Gang GONG Deyu YUAN Xuanjun 《Petroleum Exploration and Development》 2018年第6期1009-1022,共14页
Migration and accumulation simulation of oil and gas in carrier systems has always been a difficult subject in the quantitative study of petroleum geology. In view of the fact that the traditional geological modeling ... Migration and accumulation simulation of oil and gas in carrier systems has always been a difficult subject in the quantitative study of petroleum geology. In view of the fact that the traditional geological modeling technology can not establish the interrelation of carriers in three dimensional space, we have proposed a hybrid-dimensional mesh modeling technology consisting of body(stratum), surfaces(faults and unconformities), lines and points, which provides an important research method for the description of geometry of sand bodies, faults and unconformities, the 3 D geological modeling of complex tectonic areas, and the simulation of hydrocarbon migration and accumulation. Furthermore, we have advanced a 3 D hydrocarbon migration pathway tracking method based on the hybrid-dimensional mesh of the carrier system. The application of this technology in western Luliang Uplift of Junggar Basin shows that the technology can effectively characterize the transport effect of fault planes, unconformities and sand bodies, indicate the hydrocarbon migration pathways, simulate the process of oil accumulation, reservoir adjustment and secondary reservoir formation, predict the hydrocarbon distribution. It is found through the simulation that the areas around the paleo-oil reservoir and covered by migration pathways are favorable sites for oil and gas distribution. 展开更多
关键词 oil and gas MIGRATION and accumulation carrier system hybrid-dimensional MESH MIGRATION pathway geological modeling MESH generation JUNGGAR Basin western Luliang UPLIFT
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A Quantitative Method for Characterizing Transport Capability of Compound Hydrocarbon Carrier System 被引量:4
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作者 雷裕红 罗晓容 +2 位作者 张立宽 程明 宋成鹏 《Journal of Earth Science》 SCIE CAS CSCD 2013年第3期328-342,共15页
The occurrence of hydrocarbon migration in petroliferous basins depends on the balance of driving force and resistance of carriers, which restricts mostly the quantity and positions of hydrocarbon accumulation. The dr... The occurrence of hydrocarbon migration in petroliferous basins depends on the balance of driving force and resistance of carriers, which restricts mostly the quantity and positions of hydrocarbon accumulation. The driving forces of hydrocarbon migration have been quantitatively studied, whereas the migration pathways and carriers were only qualitatively discussed up to now. Establishing a compound hydrocarbon carrier system and quantitatively characterizing its transport capability are significant for understanding the dynamic process of hydrocarbon migration and revealing the hydrocarbon accumulation characteristics. It has become an innovatory trend and also a difficult topic in study of hydrocarbon migration. In this article, a method is described for using displacement pressure to quantitatively characterize the transport capability of the compound carrier system, which composed of sandstone carriers, unconformities and faults. When the weathered and leached zone rarely developed, the basal conglomerate or transgressive sandstone of unconformities can be treated as part of sandstone carriers. An empirical relationship among core porosity, air permeability, and the pore aperture radius corresponding to a mercury saturation of 10% (r 10 ) can be obtained by multiple regression. Using porosity and permeability inversed by seismic data, the displacement pressure of sandstone carriers can be calculated by the empirical relationship and Washburn Equation. Displacement pressure of fault plane can be estimated by the regression formula between fault opening index (FOI) and hydrocarbon column height it can support. This method is applied in the eastern part of south slope in Dongying (东营) depression, Bohai (渤海) Bay Basin, China, to quantitatively characterize thetransport capability of the compound carrier system of Shahejie (沙河街) Formation. The results have good agreement with data from drilling wells. This method may be a step further in study of compound hydrocarbon carrier system in petroliferous basins. It may provide the basis of coupling expulsion quantity, migration driving force and hydrocarbon carrier system to simulate hydrocarbon migration and accumulation. Therefore this will help predict hydrocarbon migration pathways and the locations ofhydrocarbon accumulation. 展开更多
关键词 hydrocarbon carrier system quantitative characterization transport capability Dongying depression displacement pressure.
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Low Cost GPS/INS Carrier Phase Integrated Navigation System
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作者 胡国辉 冯绍军 袁信 《Journal of Southeast University(English Edition)》 EI CAS 1999年第1期89-93,共5页
Integrated GPS/INS systems have applications in many different fields. It has been recognized that tightly coupled GPS/INS performance is superior to loosely coupled. The tightly coupled system uses raw data of GPS... Integrated GPS/INS systems have applications in many different fields. It has been recognized that tightly coupled GPS/INS performance is superior to loosely coupled. The tightly coupled system uses raw data of GPS as measurements, such as pseudorange, carrier phase. This paper presents two antenna GPS carrier phase measurements to stabilize the azimuth of integrated system. The test results for the integrated system show an attitude accuracy of up to 0.1° (RMS) for pitch and roll, and up to 0.03°(RMS) for azimuth when baseline is 7 8m. The system by this integration can provide the position and velocity of high accuracy too. 展开更多
关键词 NAVIGATION carrier phase tightly coupled
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The Extended Hybrid Carrier-Based Multiple Access Technology for High Mobility Scenarios 被引量:1
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作者 Ge Song Xiaojie Fang Xuejun Sha 《China Communications》 SCIE CSCD 2024年第1期53-68,共16页
The hybrid carrier(HC)system rooted in the carrier fusion concept is gradually garnering attention.In this paper,we study the extended hybrid carrier(EHC)multiple access scheme to ensure reliable wireless communicatio... The hybrid carrier(HC)system rooted in the carrier fusion concept is gradually garnering attention.In this paper,we study the extended hybrid carrier(EHC)multiple access scheme to ensure reliable wireless communication.By employing the EHC modulation,a power layered multiplexing framework is realized,which exhibits enhanced interference suppression capability owing to the more uniform energy distribution design.The implementation method and advantage mechanism are explicated respectively for the uplink and downlink,and the performance analysis under varying channel conditions is provided.In addition,considering the connectivity demand,we explore the non-orthogonal multiple access(NOMA)method of the EHC system and develop the EHC sparse code multiple access scheme.The proposed scheme melds the energy spread superiority of EHC with the access capacity of NOMA,facilitating superior support for massive connectivity in high mobility environments.Simulation results have verified the feasibility and advantages of the proposed scheme.Compared with existing HC multiple access schemes,the proposed scheme exhibits robust bit error rate performance and can better guarantee multiple access performance in complex scenarios of nextgeneration communications. 展开更多
关键词 extended hybrid carrier system high mo-Received:Jun.09 2023 Revised:Nov.20 2023 Editor:Yuanwei Liu bility communications multiple access
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Advancements in biomass gasification research utilizing iron-based oxygen carriers in chemical looping:A review
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作者 Yonghong Niu Zhengyang Chi Ming Li 《Materials Reports(Energy)》 EI 2024年第3期35-48,共14页
Biomass,recognized as renewable green coal,is pivotal for energy conservation,emission reduction,and dualcarbon objectives.Chemical looping gasification,an innovative technology,aims to enhance biomass utilization eff... Biomass,recognized as renewable green coal,is pivotal for energy conservation,emission reduction,and dualcarbon objectives.Chemical looping gasification,an innovative technology,aims to enhance biomass utilization efficiency.Using metal oxides as oxygen carriers regulates the oxygen-to-fuel ratio to optimize synthesis product yields.This review examines various oxygen carriers and their roles in chemical looping biomass gasification,including natural iron ore types,industrial by-products,cerium oxide-based carriers,and core-shell structures.The catalytic,kinetic,and phase transfer properties of iron-based oxygen carriers are analyzed,and their catalytic cracking capabilities are explored.Molecular interactions are elucidated and system performance is optimized by providing insights into chemical looping reaction mechanisms and strategies to improve carrier efficiency,along with discussing advanced techniques such as density functional theory(DFT)and reactive force field(ReaxFF)molecular dynamics(MD).This paper serves as a roadmap for advancing chemical looping gasification towards sustainable energy goals. 展开更多
关键词 Chemical looping gasification Iron based oxygen carrier Preparation of oxygen carrier system
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Joint Estimation of Carrier Frequency and Phase Offset Based on Pilot Symbols in Quasi-Constant Envelope OFDM Satellite Systems 被引量:3
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作者 Cheng Wang Gaofeng Cui +1 位作者 Weidong Wang Yinghai Zhang 《China Communications》 SCIE CSCD 2017年第7期184-194,共11页
Spectral efficiency and energy efficiency are two important performance indicators of satellite systems. The Quasi-Constant Envelope Orthogonal Frequency Division Multiplexing(QCE-OFDM) technique can achieve both high... Spectral efficiency and energy efficiency are two important performance indicators of satellite systems. The Quasi-Constant Envelope Orthogonal Frequency Division Multiplexing(QCE-OFDM) technique can achieve both high spectral efficiency and low peak-to-average power ratio(PAPR). Therefore, the QCE-OFDM technique is considered as a promising candidate multi-carrier technique for satellite systems. However, the Doppler effect will cause the carrier frequency offset(CFO), and the non-ideal oscillator will cause the carrier phase offset(CPO) in satellite systems. The CFO and CPO will further result in the bit-error-rate(BER) performance degradation. Hence, it is important to estimate and compensate the CFO and CPO. This paper analyzes the effects of both CFO and CPO in QCE-OFDM satellite systems. Furthermore, we propose a joint CFO and CPO estimation method based on the pilot symbols in the frequency domain. In addition, the optimal pilot symbol structure with different pilot overheads is designed according to the minimum Cramer-Rao bound(CRB) criterion. Simulation results show that the estimation accuracy of the proposed method is close to the CRB. 展开更多
关键词 carrier frequency offset carrier phase offset pilot symbol structure quasi-constant envelope OFDM satellite systems.
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Blind Channel Identification for Cyclic-Prefixed MIMO-OFDM Systems with Virtual Carriers 被引量:3
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作者 Jung-Lang Yu Biling Zhang +1 位作者 Yipu Yuan Wei-Ting Hsu 《China Communications》 SCIE CSCD 2020年第3期101-116,共16页
This paper applies the repetition index scheme(RIS)to the channel identification of cyclic prefixed(CP)multiple-input multiple-output orthogonal frequency division multiplexing(MIMO-OFDM)systems with virtual carriers(... This paper applies the repetition index scheme(RIS)to the channel identification of cyclic prefixed(CP)multiple-input multiple-output orthogonal frequency division multiplexing(MIMO-OFDM)systems with virtual carriers(VCs)in the environment of the number of receive antennas being no less than that of transmit antennas.The VCs will cause a rank deficiency problem in computing the subspace information.With the subcarrier mapping matrix,the received signal is simplified to remove the rank deficiency.We use the RIS scheme to generate many times of equivalent symbols so the channel identification can converge with few received OFDM blocks.The RIS scheme will convert the white noise into non-white noise.With the Cholesky factorization,a noise whitening technique is developed to turn the non-white noise back to white noise.We further analyze the necessary conditions of identifiability of channel estimation.Simulations are performed to show the superiority of the proposed method. 展开更多
关键词 OFDM MIMO VIRTUAL carrier CHANNEL identification Cholesky FACTORIZATION
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The design of monitoring communication system Based on Power line carrier 被引量:4
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作者 Wei-tao MU,Jian-jun HAO,Ping-xiang JIANG,Guo-wei LI (College of Information and Electrical Engineering,Shandong University of Science and Technology,qingdao266510,China) 《Journal of Measurement Science and Instrumentation》 CAS 2010年第S1期23-26,共4页
The design of the power line carrier communication system was introduced in this paper,DSP was adopted as the hardware platform to complete the core task.DSP sending terminal delivered the collecting data to the DSP r... The design of the power line carrier communication system was introduced in this paper,DSP was adopted as the hardware platform to complete the core task.DSP sending terminal delivered the collecting data to the DSP receiving terminal through the power line carrier, and the DSP receiving terminal send the data to PC through a serial port.The design improved the power line carrier communication system and the data transmission became faster and more reliable.The experiment results showed that the PER of the receiving data is less than 0.4%, which satisfied the power line carrier communication requirement Our design is feasible and effective. 展开更多
关键词 DSP Power LINE carrier D/A A/D
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Optimal Preview Control for Automatic Carrier Landing System of Carrier-Based Aircraft with Air Wake 被引量:1
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作者 Li Meng Zhen Ziyang +2 位作者 Gong Huajun Hou Min Huang Shuhong 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2017年第6期659-668,共10页
Carrier-based aircraft carrier landing is a special kind of tracking control problem and not suitable for classical control methods,which may miss the desired performance or result in overdesign.Therefore,we present a... Carrier-based aircraft carrier landing is a special kind of tracking control problem and not suitable for classical control methods,which may miss the desired performance or result in overdesign.Therefore,we present an optimal preview control for automatic carrier landing system(ACLS)by using state information of system,as well as future reference information,which can avoid the shortcomings of classical control methods.Since the flight performance of carrier-based aircraft is disturbed by air wake when the aircraft flies near the area of carrier stern,we design a disturbance rejection strategy to ensure that aircraft track the glide path with high precision and robustness.Further,carrier-based aircraft is a complex nonlinear system.However,the nonlinear model of carrier-based aircraft can be linearized at equilibrium landing state and decoupled into the longitudinal model and the lateral model.Therefore,an optimal preview control system is designed.The simulation results of a carrier-based aircraft show that the optimal preview control system can effectively suppress air wake.Tracking accuracy of optimal preview controller is higher than that of the proportional integral differential(PID)control system. 展开更多
关键词 carrier-based aircraft carrier landing optimal control preview control nonlinear model
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ESTIMATION OF CARRIER FREQUENCY OFFSETS FOR MIMO SYSTEMS WITH DISTRIBUTED TRANSMIT ANTENNAS 被引量:2
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作者 Deng Kai Tang Youxi Lei Xia Li Shaoqian 《Journal of Electronics(China)》 2007年第4期455-461,共7页
The problem of estimating the carrier frequency offsets in Multiple-Input Multiple-Output (MIMO) systems with distributed transmit antennas is addressed. It is supposed that the transmit antennas are distributed while... The problem of estimating the carrier frequency offsets in Multiple-Input Multiple-Output (MIMO) systems with distributed transmit antennas is addressed. It is supposed that the transmit antennas are distributed while the receive antennas are still centralized, and the general case where both the time delays and the frequency offsets are possibly different for each transmit antenna is considered. The channel is supposed to be frequency flat, and the macroscopic fading is also taken into consideration. A carrier frequency offset estimator based on Maximum Likelihood (ML) is proposed, which can separately estimate the frequency offset for each transmit antenna and exploit the spatial diversity. The Cramer-Rao Bound (CRB) for synchronous MIMO (i.e., the time delays for each transmit antenna are all equal) is also derived. Simulation results are given to illustrate the per- formance of the estimator and compare it with the CRB. It is shown that the estimator can provide satisfactory frequency offset estimates and its performance is close to the CRB for the Signal-to-Noise Ratio (SNR) below 20dB. 展开更多
关键词 Multiple-Input Multiple-Output (MIMO) Distributed antenna carrier frequency offset estimation Maximum Likelihood (ML) Cramer-Rao Bound (CRB)
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THE PERFORMANCE OF MT-CDMA SYSTEM IN THE PRESENCE OF CARRIER FREQUENCY OFFSET 被引量:1
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作者 Huang Ying Yang Wei Liu Junying 《Journal of Electronics(China)》 2007年第1期128-132,共5页
In this letter,the sensitivity of an uplink Multi-Tone Code-Division Multiple Access (MT-CDMA) system to the Carrier Frequency Offset (CFO) is investigated. The analytical expression for the Bit Error Rate (BER) of up... In this letter,the sensitivity of an uplink Multi-Tone Code-Division Multiple Access (MT-CDMA) system to the Carrier Frequency Offset (CFO) is investigated. The analytical expression for the Bit Error Rate (BER) of uplink MT-CDMA in the presence of CFO is derived in a multipath Rayleigh fading channel which is verified through simulations. Both Maximal Ratio Combining (MRC) and Equal Gain Combining (EGC) are considered in combining multipath signals in the analysis. It is found that the BER performance can be improved with the number of multipath increasing in the presence of CFO. 展开更多
关键词 Multicarrier (MC) Code-Division Multiple Access (CDMA) carrier Frequency Offset (CFO)
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New Insight into the Development of Oxygen Carrier Materials for Chemical Looping Systems 被引量:9
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作者 Zhuo Cheng Lang Qin +1 位作者 Jonathan A. Fan Liang-Shih Fan 《Engineering》 2018年第3期343-351,共9页
Chemical looping combustion (CLC) and chemical looping reforming (CLR) are innovative technologies for clean and efficient hydrocarbon conversion into power, fuels, and chemicals through cyclic redox reac- tions. ... Chemical looping combustion (CLC) and chemical looping reforming (CLR) are innovative technologies for clean and efficient hydrocarbon conversion into power, fuels, and chemicals through cyclic redox reac- tions. Metal oxide materials play an essential role in the chemical looping redox processes. During reduc- tion, the oxygen carriers donate the required amount of oxygen ions for hydrocarbon conversion and product synthesis. In the oxidation step, the depleted metal oxide oxygen carriers are replenished with molecular oxygen from the air while heat is released. In recent years, there have been significant advances in oxygen carrier materials for various chemical looping applications. Among these metal oxide materials, iron-based oxygen carriers are attractive due to their high oxygen-carrying capacity, cost ben- efits, and versatility in applications for chemical looping reactions. Their reactivity can also be enhanced via structural design and modification. This review discusses recent advances in the development of oxy- gen carrier materials and the mechanisms of hydrocarbon conversion over these materials. These advances will facilitate the development of oxygen carrier materials for more efficient chemical looping technology applications. 展开更多
关键词 Chemical looping Oxygen carrier Hydrocarbon conversion Ionic diffusion MECHANISM
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Comparisons of Short-Prefix Based Channel Estimation in Single-Carrier Communication Systems 被引量:1
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作者 Huilei Li Shiwen Fan +2 位作者 Lisha Gong Guobing Cheng Shaoqian Li 《Communications and Network》 2013年第3期398-402,共5页
In this paper, we compare the performance between channel estimation based on compressed sensing (CS) and time-domain least square (LS) for single-carrier (SC) communication system. Unlike the conventional channel est... In this paper, we compare the performance between channel estimation based on compressed sensing (CS) and time-domain least square (LS) for single-carrier (SC) communication system. Unlike the conventional channel estimation techniques such as frequency domain LS which is used in the condition that the length of pilot sequence is equal to data sequence, the estimation scheme based on CS requires smaller length of pilot sequence. In this paper, the corresponding system structure is presented. Zadoff-Chu sequence is used to generate the pilot sequence, which is shown to perform better in forming measurement matrix of CS than pseudo random sequence. Simulation results demonstrate that channel estimation based on CS achieves a better bit error rate (BER) performance than time domain LS with a smaller pilot sequence and thus raising data rate of the SC communication system. 展开更多
关键词 Compressed SENSING Time DOMAIN Least SQUARE Single-carrier Communication system Zadoff-Chu Se-quence
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Fiber Bragg Grating Sensor Array System Based on Digital Phase Generated Carrier Demodulation and Reference Compensation Method 被引量:2
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作者 Jun He Fang Li Hao Xiao Yu-Liang Liu 《Journal of Electronic Science and Technology of China》 2008年第4期389-392,共4页
A novel fiber Bragg grating (FBG) sensor array system based on digital phase generated carrier (PGC) demodulation and reference compensation method is proposed and set up. Experimental results confirm that the dig... A novel fiber Bragg grating (FBG) sensor array system based on digital phase generated carrier (PGC) demodulation and reference compensation method is proposed and set up. Experimental results confirm that the digital PGC demodulation can be used for wavelength-division-multiplexed FBG sensor array and the reference compensation method can reduce the environmental interference by approximately 40 dB in the frequency range from 20 Hz to 2 kHz. The minimum detectable wavelength-shift of the sensor system is 1 × 10^-3 pm/Hz^1/2. 展开更多
关键词 Fiber Bragg grating (FBG) sensor phase generated carrier (PGC) reference compensation method wavelength division multiplexing.
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Carrier Frequency Offset Estimation for FM and Symbiotic FM Radio Data System Hybrid Signal
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作者 Fei Wang Xi Chen +2 位作者 Aidong Men Lei Zhang Sheng Wu 《China Communications》 SCIE CSCD 2020年第1期129-139,共11页
The symbiotic FM radio data system(SRDS)is a radio data system that a specially designed OFDM signal co-lives with FM signal,which enables a significantly higher data rate than existing radio data systems.The cyclic p... The symbiotic FM radio data system(SRDS)is a radio data system that a specially designed OFDM signal co-lives with FM signal,which enables a significantly higher data rate than existing radio data systems.The cyclic prefix of the OFDM symbol has the same length as the OFDM body,which enables the analytic separation of the co-channel OFDM and FM signal at receiver side,utilizing the fact that the OFDM body and prefix is equal.In this work,we show that the OFDM body and prefix cannot be viewed as equal when there is sufficient carrier frequency offset(CFO).Thus,we propose a two-step CFO estimation algorithm for FM and SRDS hybrid signal.The first step estimates the coarse CFO by exploring the characteristics of the FM signal.Once the coarse CFO is removed,the residual CFO is small enough for FM and OFDM separation.The second step fine estimates CFO from the OFDM-only signal using its repeated PN structure after the separation.Detailed mathematical equations are formulated and simulation results are given.The results show that the proposed algorithm works fine with the simulation setup and has a final residual CFO less than 3.9Hz. 展开更多
关键词 FM OFDM Symbiotic radio data system carrier offset estimation
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Non-Overlapping Conditions to Enable Multi- Dimensional Behavioral Models/DPDs for Multi-Band or Non-Continuous Carrier Aggregation Systems
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作者 Cuiping Yu Ziyuan Zhang 《China Communications》 SCIE CSCD 2017年第2期30-39,共10页
To linearize the multi.band PAs/transmitters, a serial of multi.band predistortion models based on multi.dimensional architecture have been proposed. However, most of these models work properly only for the signals wh... To linearize the multi.band PAs/transmitters, a serial of multi.band predistortion models based on multi.dimensional architecture have been proposed. However, most of these models work properly only for the signals whose harmonic and intermodulation products of carriers' non.overlap with the interested fundamental bands. In this paper, the non.overlapping conditions for dual.band and tri.band signals are derived and denoted in the form of closed.form expression. It can be used to verify whether a given dual.band/multi.band signals can be linearized properly by these multi.dimensional behavioral models. Also the conditions can be used to plan the frequency spacing and maximum bandwidth of a multi.band or non.continuous carrier aggregation signal. Several dual.band and triband signals were tested on the same PA, by employing 2.D DPD and 3.D DPD behavioral models. The measurement results show that the signals which don't satisfy the non.overlapping conditions cannot be linearized well by the multi.dimensional behavioral models which does not take the harmonic and intermodulation products of carriers' into account. 展开更多
关键词 PREDISTORTION multiband power amplifiers behavioral model carrier aggregation
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ICI elimination of M-band wavelet multi-carrier modulation system
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作者 彭章友 刘艳艳 张兴 《Journal of Shanghai University(English Edition)》 CAS 2010年第1期6-11,共6页
To solve the inter carrier interference (ICI) elimination problem of an M-band wavelet multi-carrier modulation system, this paper analyzes the principle of the ICI caused by the Doppler frequency shift and its math... To solve the inter carrier interference (ICI) elimination problem of an M-band wavelet multi-carrier modulation system, this paper analyzes the principle of the ICI caused by the Doppler frequency shift and its mathematical expression based on the M-band wavelet multi-carrier modulation system model. Through the analysis of the mathematical expression and combining with the perfect reconstruction conditions of the filter banks, we propose the design conditions of an M-band filter to reduce and eliminate the ICI. The impulse response model of the filter design conditions and an iterative algorithm is also established. The simulation results show that the proposed ICI reduction and elimination methods can effectively improve the system performance. 展开更多
关键词 M-band wavelet multi-carrier modulation Doppler frequency shift inter carrier interference (ICI) impulseresponse
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